[libc++] Use addressof in list.

This addresses the usage of `operator&` in `<list>`.

(Note there are still more headers with the same issue.)

Reviewed By: #libc, Quuxplusone, ldionne

Differential Revision: https://reviews.llvm.org/D112654

GitOrigin-RevId: 4732dd301086ce056d869eded4e1543fcb45506d
13 files changed